One method for examining the gastrointestinal tract for the existence of polyps and other clinically relevant features that may indicate regarding the potential of cancer is performed by swallowing an imaging capsule that travels through the gastrointestinal tract and view the patients situation. In a typical case the trip can take between 24-48 hours after, which the imaging capsule exits in the patients feces. Typically the patient swallows a contrast agent to enhance the imaging ability of the imaging capsule. Then the patient swallows the imaging capsule to examine the gastrointestinal tract while flowing through the contrast agent. The imaging capsule typically includes a radiation source, for example including a radioisotope that emits X-rays and/or Gamma rays. The radiation is typically collimated to allow it to be controllably directed toward a specific area during the imaging process. In an exemplary case the imaging capsule is designed to measure X-Ray fluorescence and/or Compton back-scattering and transmit the measurements (e.g. count rate) to an external analysis device, for example a computer or other dedicated instruments.
U.S. Pat. No. 7,787,926 to Kimchy the disclosure of which is incorporated herein by reference, describes details related to the manufacture and use of such an imaging capsule.
Use of an imaging capsule exposes the user to radiation, which may be potentially harmful. Accordingly, it is of interest to limit the user's exposure to radiation when not necessary, for example while the imaging capsule is located in positions that do not need to be measured. Typically, the imaging capsule may be designed with shutters that can be instructed to block the emission of radiation when not needed. However, there still exists the hazard that in case of malfunction of the imaging capsule, for example in case of a power failure the shutters may be stuck in the open position and radiation may be emitted without constraint.
It is thus desirable to design a fail-safe radiation blocking mechanism that automatically blocks the emission of radiation, only allowing radiation to be emitted if power is available and the device provides an instruction to allow radiation to be emitted.
Another consideration is power consumption. It is desirable to conserve energy and scan with the capsule only when movement of the capsule in the colon occurs, therefore, the concealment mechanism should be designed to use as little power as possible yet to enable activation and scanning by electrical control.